Overworld mobs spawn in the end

Attached a world created in 1.0.0 where I was able to repro the bug for testing purposes.

I was attempting to create an Ender man farm (Ender Ender) but overworked mobs were spawning and not enough Ender men were spawning. In the PC Ender men get afro on Ender mites up to 64 blocks away yet I did some testing by making a semi circle with a radius of 30 about the center island height above the void so that I was out of range of the island and even then I had one Ender men out of about 30 other overworld mobs so if you could fix that, that would be great and make Ender men afro if within at least 32 blocks of an endermite.

Affects 1.0.2

I have the same problem of a lower spawn rate of enderman with additional mobs spawning in my farm on windows 10 version 1.0.2

Is this affecting 1.0.3.0?

Confirmed 1.0.3. Interestingly, I tried to build an ender farm with an endermite. "Mitey" was only about 100 blocks from the mainland. I was getting endermen to spawn on the platform but nothing like the rates on the mainland. So I looked on the wiki and saw that it should be at least 128 blocks away. So I counted this time and moved "Mitey" out 30 more blocks. I haven't had a single enderman spawn on the new platform. Only overworld mobs. On the platform that was on the cusp of the 128 block range, I would get a mix of endermen and overworld mobs. Probably depended on which blocks were on which side of the 128 block range as to if it spawned an enderman or an overworld mob.

This is also affecting 1.0.4 (Win 10, Realm)

I set up an enderman farm in the end, near Y=0 and about 200 blocks from the main island. I have yet to see an enderman spawn on the pad, but I've got plenty of creepers, zombies, and spiders.

@unknown, was this farm built in the release version of 1.0.4 or earlier? Newly-explored chunks should not be affected by this bug, as far as I can tell from my testing.

I'm not building my Enderman farm in my realm until I can confirm a resolution. Therefore, it is full of unexplored chunks so I just downloaded a copy to my iPad with version 1.0.4. It did work a bit differently than I saw in 1.0.3. The platform I constructed did spawn Endermen, though slowly. Whereas it still spawns overworld mobs prolifically.

I can confirm this remains an issue in 1.0.5 within explored chunks. The issue is however resolved within unexplored (or newly explored) chunks. (Only enderman and no overworld mobs will spawn in newly explored chunks) If this is a biome issue, does the code allow for previously explored chunks in existing worlds to be updated with the correct biome type when opened in an upcoming version?

@unknown, as far as I know, it doesn't. There was a biome-corrupting bug back during the 1.0 beta, if I remember correctly, and worlds from that version still have their old chunks with messed-up biomes.

Also, can anyone else confirm that this bug is fixed for new chunks in 1.0.5.54 and/or 1.0.6.0?

Fixed as of 1.0.5.54.

Important Note: This bug has been fixed, and new chunks should spawn endermen as expected, but existing chunks will still be affected by this bug, since their biome or something was messed up. Unfortunately I don't think these chunks can be retroactively fixed in any future updates. Anyone who built an enderman farm in previous versions will just have to go build it somewhere else, I'm afraid. On the bright side, maybe you could make an overworld hostile mob farm in the older chunks instead?

This issue may need to be reopened for v1.0.5 Win 10 64 bit... Overworld mobs are still spawning in newly explored areas although they are spawning at much reduced rates than we were seeing before. I created a new world today to test an enderman farm. Blocked out 144 blocks from island, then created a spawning pad at least 144 blocks out. Enderman spawn there at higher rates as expected, however overworld mobs also do spawn at times. I've seen skeletons, creepers, spiders and zombies so far.